I'd like to see a view from above, but from these images I would plump for the Birch Sawfly, Cimbex femoratus. Although several species of large cimbycid sawfly are be no means rare you have luck to see them - right place at the right time.

I do have a half reasonable picture taken from above but what I can tell you is that the abdomen was entirely black to match the rest of the fly except for a bright yellowish, almost fluorescent patch just behind the thorax on the front of the abdomen.